<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div class="box">我是内容</div>
    <script>
        const box = document.querySelector('.box')
        // box.innerText = '我是一个盒子'
        // console.log(box.innerText);
        
        box.innerHTML = '<strong>我是一个盒子</strong>'
        console.log(box.innerHTML);
    </script>
    
</body>
</html>